Question of the Day

Whose side of the story do you believe?

YOSEMITE NATIONAL PARK, Calif. (AP) — After the great 1906 earthquake, searching for reliable power and drinking water, San Francisco looked at the soaring granite of Yosemite’s Hetch Hetchy Valley and saw walls for a reservoir.

Conservationists like John Muir were appalled that anyone might flood what he called “a grand landscape garden, one of nature’s rarest and most precious mountain temples.”

But after one of the country’s first major environmental battles — a struggle that transformed Mr. Muir’s Sierra Club into a political force — the O’Shaughnessy Dam was completed in 1923.

Today, even as the Hetch Hetchy system delivers some of the country’s highest quality drinking water to 2.4 million San Francisco area residents, environmentalists continue to argue for restoring the valley — a debate that was intensified in July when a state review found that the job would be “technically feasible” for an estimated $3 billion to $10 billion.

Conservationists see an opportunity to restore what Mr. Muir called a “wonderfully exact counterpart” to Yosemite Valley, the park’s more famous attraction, known for towering monuments like El Capitan, as well as its clogged campgrounds and roadways.

They say it’s possible to dismantle the 312-foot concrete dam, replace the lost water storage downstream on the Tuolumne River and find other sources of clean electricity.

The city and other political leaders, however, pounced on the multibillion-dollar cost estimate.

They also argue that the project would compromise San Francisco’s water supply when California needs more water storage and electricity, not less, given its growing population and predictions that global warming could lead to more droughts and melting snowpacks.

What’s more, they say, Yosemite’s visitors enjoy the valley’s dramatic landscape and 7-mile-long reservoir just as they are now.

“It’s a real misplaced priority,” said Susan Leal, general manager of the Public Utilities Commission, which manages the Hetch Hetchy water system.

Restoration also would require congressional backing because Yosemite is a national park, and the idea has little support from federal lawmakers.

Democrat Sen. Dianne Feinstein, a former San Francisco mayor, said the new study confirmed the project is “unwarranted and the cost is indefensible, particularly given the tremendous infrastructure needs facing our state.”

The latest restoration push began in 2001 when San Francisco began planning a $4.3 billion upgrade of the Hetch Hetchy system.

Studies by the University of California at Davis and Environmental Defense each argued that it was possible to drain the reservoir and replace most of the water storage capacity with expanded reservoirs downstream. They projected that native plants and animals would return to the valley floor within years.